Feeling guilty about wanting to quit work

My daughter is 5.5 months old and I just feel like I can’t take it anymore. I returned to work after 12 weeks maternity leave and I really never mentally returned. I have a physically and mentally demanding job as a physical therapist. I returned 30 hours/wk but it’s still exhausting- waking up at 5:30, pumping, getting myself and baby ready, making sure she has enough bottles, going to work, pumping at work, dealing with patients, and then coming home to a full time mommy job. My husband gets home around 6 and helps as much as he can, but he’s exhausted too and baby only wants me at bedtime. On top of it, my daughter hasn’t slept more than 2 hour stretches since she has been born, and since I’m breastfeeding, I get up with her at night. I haven’t slept longer than 2 hours in almost 6 months. I don’t know if I have PPD or sleep deprivation, but I’m so burned out. I am contemplating quitting, things would be tight, but we could do it. Im afraid to give up my job and feeling guilty that I can’t handle it all, plenty of moms work. I guess I just need to vent, there have to be other mamas out there who feel this 😞